Well what I have as of now are (which also includes computers since other members are mentioning them):

Amstrad CPC 464+
2X Commodore Amiga A600 (one has a faulty sound chip)
2X Commodore A1200 (one has a Blizzard 64MB Graphics expansion card in it)
Custom built PC ASUS P5N-E SLI
Toshiba L300D-1BV
SEGA Master System (standard with no game built-in, unless you count the hidden snail game)
3X SEGA Master System II (two with Sonic 1 built-in, the other with Alex Kidd built-in)
3X SEGA Mega Drive (two standard ones along with the other one that has the 16 bit in gold)
SEGA Mega Drive II
Super Nintendo
Sony Playstation SCPH-7502
2X Sony Playstation SCPH-9002 (one standard, the other one has a mod chip)
Nintendo Gamecube /w Gameboy Player (use it to play old gameboy titles, also to play GBA games)
2X Nintendo DS (phat DS but the touch screen don't work and the other being a Lite)
Nintendo Wii
limited edition Crystal XBOX (DVD drive needs fixed when I can be bothered to sort it)
XBOX 360 Pro